This month brings the release of a handful of new movies and a smattering of rereleases, as well as another sort of picture that is neither old nor new but just a little bit blue. Let's call these the films that time - or, to be more accurate, the distributors - forgot. Not for these mildewed productions the corporate fanfare afforded a blockbuster like Baz Luhrmann's Australia. Nor will they enjoy the twinkly-eyed nostalgia that will greet the umpteenth revival of White Christmas. The films that no one seemed to want to release inspire not anticipation nor fondness but scepticism - a feeling on the cinemagoer's part that someone is trying to pull a fast one. If only that were the case; on the contrary, the progress of the Hungarian movie The Man from London - from Cannes premiere to UK release in just 18 months - has just been inordinately slow.

Béla Tarr's impressively steely drama (a mere doodle at 140 minutes, compared with the same director's 450-minute Sátántangó) played at Cannes a year and a half ago, but is only reaching cinemas next week. Similarly, Otar Iosseliani's bittersweet comedy Gardens in Autumn was made in 2006, scheduled for release here in 2007 and is finally arriving in the last days of 2008. What's the hold-up? Well, both films are distributed by Artificial Eye, which tends to schedule its predominantly arthouse releases with pernickety care rather than casting them cruelly into the marketplace. Finding what the industry call "exhibition space" is also tricky in this multiplex-dominated era. But this distributor was also the subject of a recent takeover, so perhaps The Man from London and Gardens in Autumn got mislaid in the flurry of desk-clearing. If it can happen with a stapler or a hole-punch, why not a movie?

Or maybe the films were considered so exquisitely special that they needed time to settle, like fine wines, before the grand decanting. But it's no good. However you dress it up, these titles have been left on the shelf to accumulate not only dust, but also pernicious rumours about precisely why they are being hidden from public view. Can't you imagine all the other films laughing and pointing? Of course, it would be far worse if they were made in Hollywood, where any announcement that a movie's release is being pushed back is tantamount to confessing that the director's gone nuts, the leading lady's addicted to painkillers and the stuntmen are dead but they can't find the bodies. (Witness the buzz of tittle-tattle when the latest Harry Potter got shoved from this Christmas to next summer to fill a hole in the Warner Bros schedule.)

On one hand, it seems somehow fitting that Tarr, famed for his leisurely pacing and protracted takes, should have to wait over a year and a half for his latest work to open. But the real reason that specialist or arthouse pictures can get left in limbo in this way is that there's no hurry, no expiration date. If you've pumped your money into Breakdance 2: Electric Boogaloo, then you'll want to put that movie into cinemas before everyone gets into jiving or jitterbugging instead. If you've got a Convoy on your hands, then best offload it quickly, before the CB craze dies down. But what's the hurry with a Tarr or an Iosseliani? If it looks good now, it's going to look just as fine if you hold back the release until the polar ice-caps are nothing more than the answer to an obscure pub quiz question, and we're all kayaking to work.

Not that this rationale applies to every film. There was a small window of opportunity for the "mumblecore" subgenre early in 2007, when the director Andrew Bujalski attracted rave reviews here for his films Funny Ha Ha and Mutual Appreciation, during which any mumblecore movie needed to open quickly, or else wither and die. One such film, Hannah Takes the Stairs, finally arrives here in January, 18 months after its US release. Odds against the film's commercial chances being unaffected by the stale whiff of rejection hanging round it currently stand at 18 kazillion to 1.